Abstract
Abstract
Simple superpositions of Laguerre–Gauss beams illustrate, counterintuitively, the difference between two quantities that are commonly conflated: the component of orbital angular momentum ⟨l⟩ in the propagation direction z, and the total topological charge S, which is the algebraic sum of the charges of vortices piercing any plane perpendicular to z. The examples illustrate two contrasting situations: ⟨l⟩ = 0, S ≠ 0, and ⟨l⟩ ≠ 0, S = 0. In the second situation, not only is the total charge zero but also there are no vortices in the infinite half-space beyond the beam waist plane z = 0.
Funder
National Natural Science Foundation of China
Leverhulme Trust
Subject
General Physics and Astronomy,Mathematical Physics,Modeling and Simulation,Statistics and Probability,Statistical and Nonlinear Physics
Reference29 articles.
1. Dislocations in wave trains;Nye;Proc. R. Soc. A,1974
2. Much ado about nothing: optical dislocation lines (phase singularities, zeros, vortices …);Berry,1998
3. Orbital angular momentum of light and the transformation of Laguerre–Gaussian laser modes;Allen;Phys. Rev. A,1992
Cited by
20 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献